DUBAI, United Arab Emirates — Marooned outside South Africa, Ajay Gupta has been obsessively following the news from home with increasing frustration. Nearly every day for the past couple of months, witnesses at a high-profile inquiry on corruption have painted his family as the masterminds of the government looting that has engulfed the nation.

The accusations infuriate him. But Mr. Gupta and his two brothers, who left South Africa early this year when President Jacob Zuma was forced out of power, have no plans to go back and give their side of the story — at least not yet. They say they fear wrongful arrests if they return to South Africa, a country where their power appeared uncontested less than a year ago.

The inquiry’s leaders have rejected the Guptas’ offers to testify by video conference or other means — creating the possibility that a wide-ranging government inquiry determined to ferret out the truth will not hear from some of the main characters.

“I’m not saying that I’m not coming to the commission,” Mr. Gupta, the oldest brother, said in Dubai, where the family is now based. “I will, but not this moment.”

He added, “I want to clear my name.”

South Africa’s inquiry into state corruption has gripped the nation with its glimpses into the byzantine ways power has been amassed and wielded within the African National Congress, the party that has run the country since the end of apartheid. Scheming politicians, powerful bankers and prominent officials have featured prominently in the ever-lengthening cast of characters.

The hearings, which began two months ago and could last for years, are supposed to shed light on the corruption that has consumed South Africa in recent years. And the Guptas are at the heart of it — accused of having built a business empire based on graft through their ties with Mr. Zuma, his family and allies.

Some experts say that the hearings could serve as a catharsis for a corruption-tainted era in the nation’s history, the way the post-apartheid Truth and Reconciliation Commission did two decades ago. That is, if a true picture emerges from the corruption hearings.

In his first extensive interview since leaving South Africa, Mr. Gupta, 53, forcefully rejected accusations made in the hearings against his family, including that he and his brothers offered ministerial positions on the president’s behalf in return for favors. Instead of being the architects of government corruption — what has become known in South Africa as state capture — Mr. Gupta said his family was caught in the crossfire between rival A.N.C. factions and their business allies.

The family, he said, was the victim of politically motivated law enforcement authorities and a witch hunt that could not stand scrutiny in court. Despite the many accusations that his family essentially defrauded the government by siphoning off enormous sums of money from government contracts and other deals, Mr. Gupta noted that prosecutors had charged them only once, in a case involving a dairy farm.

In significant setbacks, prosecutors have twice failed to prove that the money siphoned from the dairy farm project, called Estina, directly benefited Mr. Gupta or other companies linked to the Gupta family. A high court judge released most of the assets frozen in the case in March, and the court ruled in favor of the companies linked to the Guptas again in May. A separate criminal case is still underway.

The office of the former Public Protector, a government authority that investigates misconduct, called for the creation of an inquiry in a report on corruption in 2016. Mr. Zuma unsuccessfully tried to block the investigation a couple of months before he was ousted from power in February by his deputy, Cyril Ramaphosa.

The government of Mr. Ramaphosa, who has made it a priority to fight corruption, had no choice but to endorse the inquiry, experts said.

“The A.N.C. tried to duck and dive, but it got to a point where it had to push for a commission itself,” said Prince Mashele, a political analyst and the author of “The Fall of the A.N.C. Continues: What Next?” “So it was under pressure. It’s not something that came from the A.N.C.”

With national elections scheduled for next year, experts said that the inquiry was intended to give voters the impression that Mr. Ramaphosa’s government was cracking down on corruption. Most importantly, it could help rehabilitate the party’s image by establishing the narrative that corruption was the result of a few bad apples in the party and, above all, the Gupta family.

“Instead, the inquiry has revealed that the entire party is rotten,” Mr. Mashele said.

In recent weeks, the actions of some of Mr. Ramaphosa’s closest allies have come to light in the hearings, indicating that they were not completely innocent. A.N.C. leaders reacted angrily, saying that the party was “not on trial.”

The most damaging report centered on Nhlanhla Nene, widely considered, until a few weeks ago, as a hero in the fight against corruption in the Zuma administration. This month, Mr. Nene testified that he had been fired by Mr. Zuma as finance minister in late 2015 after he refused to endorse a nuclear energy deal that critics said was meant to enrich the former president’s business allies — a pivotal episode in the A.N.C.’s recent history.

Mr. Nene, who had said in the past that he had never visited the Guptas’ residence, said he had in fact done so on multiple occasions — even after becoming finance minister in 2014.

“I was not requested to do anything to benefit the Gupta family or Mr. Ajay Gupta, nor was I offered any inducement,” he said in his statement to the commission.

Mr. Nene issued an apology to the nation about the visits to the Gupta home, and he was forced to resign last week.

Mr. Gupta, though, said there had been nothing wrong with Mr. Nene’s visits to his home. “Forget Nene,” he said. “We never asked any minister for any commercial benefit.”

Over the years, Mr. Gupta said, countless senior politicians from the A.N.C. and the opposition had visited his home.

“Who did not come and meet me? Or I not meet with them?” Mr. Gupta said.

He added: “Meeting with people, there’s nothing wrong. Every business organization meets with the politicians and the people.”

In a hearing, Mr. Gupta’s lawyer, Michael Hellens, argued on his behalf that the inquiry’s goal of seeking the truth would be undermined without the brothers’ testimony.

“You will not have heard the evidence of the Guptas,” Mr. Hellens said. “Now what value will that finding be?”

Under the rules governing the commission, any evidence, including what may be inadmissible in a court of law, can be accepted. But the commission leader, Raymond Zondo, the deputy chief justice of the nation’s highest court, ruled that the brothers would not be allowed to testify unless they returned to South Africa. Allowing them to testify from abroad, he said, would be “special treatment.”

William Gumede, a political scientist at the University of Witwatersrand, said that even without the Guptas’ testimony, the hearings were yielding answers.

“You’re getting the info, and you’re building a picture, so when you get to the Guptas, you know exactly what you’re looking for,” he said.

In Dubai, Mr. Gupta argued that the commission was simply not interested in hearing his side of the story.

In one of the most explosive hearings, a former deputy finance minister, Mcebisi Jonas, said Mr. Zuma’s son, Duduzane, took him to the Gupta residence in Johannesburg in late October 2015. Duduzane Zuma had worked for years for the Gupta family.

The Gupta brother, he said, offered to make him rich in return for favorable treatment in the position.

“Mr. Gupta repeated that they had information on me and that if I suggested that the meeting had occurred, they would kill me,” Mr. Jonas said in a statement.

In the Public Protector’s 2016 report, Mr. Jonas said that the Gupta brother who made him the offer was Ajay, the oldest. But in the recent hearing, Mr. Jonas said that he was “relatively certain” that it was Ajay. He raised the “possibility that it might have been Rajesh,” the youngest Gupta brother.

In the interview, Ajay Gupta contended that he was not home during the meeting between Mr. Jonas and Mr. Zuma’s son. His brother Rajesh “did not meet with Jonas at all,” Mr. Gupta said. “He just came into the room for a fraction of a second, and say hello to Dudu.”